A Saudi man being sought by the FBI because he may be plotting terrorist attacks against U.S. targets has been linked to Jose Padilla, an American citizen charged with plotting to detonate a radiological "dirty bomb" in the United States.

The FBI on Thursday asked law enforcement agencies and the public to be on the lookout for Adnan G. El Shukrijumah, 27, who senior law enforcement officials said has received flight training and possesses a Florida driver's license.

"El Shukrijumah is possibly involved with Al Qaeda terrorist activities and, if true, poses a serious threat to U.S. citizens and interests worldwide," the FBI said in a statement.

Officials said El Shukrijumah's organizing capabilities are comparable to those of Mohammed Atta, the suspected organizer of the Sept. 11 terror attacks. Fifteen of the 19 hijackers were Saudis and some, including Atta, received flight training in Florida.

A federal law enforcement official, speaking Friday on condition of anonymity, said authorities were tipped to El Shukrijumah by Khalid Shaikh Mohammed, Al Qaeda's chief operational planner who was arrested March 1 in Pakistan.

Information recovered after Mohammed's capture includes references to Padilla and El Shukrijumah, who at one time lived near each other in the Miami area, according to the official.

The FBI previously has said that Mohammed met with Padilla in early 2002. Padilla was arrested last May as an "enemy combatant" and is in federal custody.

Meantime, the FBI is intensifying its interviews with Iraqi-born people living in America. FBI Director Robert Mueller said the bureau, in conjunction with police departments nationwide, is redoubling its anti-terrorism efforts now that war with Iraq is at hand.

"We are bringing to bear the full weight of our resources, expertise and partnerships," Mueller said Thursday. "We are running down every lead, responding to every threat, coordinating with every partner and doing our utmost to keep terrorists from striking back."

The FBI says the interviews are aimed at rooting out any potential terrorist attacks planned by Iraqi operatives or sympathizers. The interviews were focused on about 11,000 Iraqis who either have traveled to their homeland recently or had some contact with Iraq's military, law enforcement officials said.

Teams of FBI and immigration officials also have begun arresting Iraqis who are in the United States illegally, mainly for visa violations. A statement from the Bureau of Immigration and Customs Enforcement said the operation was aimed at "taking individuals off the street who might pose a threat to the safety and security of the American people" and said they were targeted based on intelligence information.

One official said the number of detainees was at least several dozen, but exact numbers weren't available.

Relatives of El Shukrijumah denied any connection to Al Qaeda or terrorism, adding that he was living with his family in Morocco. His father, Gulshair El Shukri, told the South Florida Sun-Sentinel that his son did not know how to pilot a plane.

Florida motor vehicle records show that El Shukrijumah committed at least five traffic violations between 1996 and 1999.

In California, Highway Patrol Commissioner Dwight Helmick told reporters that police are double-checking tanker trucks hauling gasoline and other combustible substances because El Shukrijumah "has been known to utilize gasoline-type haulers" in the past. Helmick did not elaborate on that potential threat but said he had been briefed on the FBI alert.

El Shukrijumah is described as about 5-foot-4 and 132 pounds, though he may be heavier. He has black hair, black eyes and a Mediterranean complexion, and may be wearing a beard, the FBI said.

Although born in Saudi Arabia, the FBI said El Shukrijumah carries a passport from Guyana. He also could have passports from Saudi Arabia, Canada or Trinidad.

He has used many aliases, including Adnan G. El Shukri Jumah, Abu Arif, Ja'far Al-Tayer, Jaffar Al-Tayyar, Jafar Tayar and Jaafar Al-Tayyar.